Finite temperature corrections to relic density calculations

In this paper we evaluate finite temperature corrections to the dark matter relic density within the context of minimal supersymmetry with a neutralino as the lightest supersymmetric partner (LSP). We identify several regions of parameter space where the weakly interacting massive particle (WIMP) annihilation cross section is especially sensitive to small corrections to the underlying parameters. In these regions, finite temperature effects have the potential to be important. However, we shall show by explicit calculation that these effects are small. In the regions we investigated, the maximal corrections are on the order of ${10}^{-4}$ and are therefore negligible compared with theoretical and experimental uncertainties.

Figure 1

One loop diagrams contributing to the self-energy of the stau.

Figure 2

Feynman diagram contributing to the neutralino self-energy at one loop order and in the limit of a plasma populated by light SM particles.

Figure 3

Thermal corrections to the masses of the stau (solid line) and lightest neutralino (dashed line) in the stau coannihilation region. The values are scaled by the zero-temperature mass splitting.

Figure 4

Feynman diagrams contributing, at one loop order, to the helicity breaking mass of the standard model fermions.

Figure 5

Thermal correction to the helicity breaking mass operator of the bottom quark (solid line) and tau lepton (dashed line).

Figure 6

Feynman diagram contributing to the $A^0$ boson self-energy.

Figure 7

Thermal correction to the width of the $A^0$ boson.